Automatic selecting-switch.



C W CLEIVHVIEB AUTOMATIC SELEING SWU-CH.

Y APPLCATION FILED )UNI-:15. |912. 1L Il www@ web. 26,1918" MYX/5555 tutt sranarran tiraron CHARLES W. CLMMER, 0F DAYTN, OHIO, ASSIGNOR TO AUTOMATC ELECTRIC COM- y YIPANY, OF CHICAGO, ILLINOIS, A CORPORATIDN 0F ILLINOIS.

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Speciication of Letters Patent.

Patented lleb. 26, little.,`

Application filed .T une 1,5, 1912Y Serial No. 703,786.

To ol whom 'it may concern.'

Be it known that I, CHARLES W. CLEM- ninn, a citizen of` the United States of America, and resident of Dayton, Montgomery county, Ohio, have inventedcertain new and useful Improvements in Automatic SelectingSwitches, of which the following is a speciiication. Y

My invention relates to improvementsin selecting switches for automatic telephone systems, and more particularly to switches of the side switchless type-that is, a select; ing switch having motion in two intersecting planes, which switch is controlled without the use ofthe customary and well-known side switch. i f v The object of my invention is to provide a switch ofthis type in which the construction and operation are simplied and improved. l

Among the novel features l provide im-v proved means for producing the automatic rotation of the switch 1n selecting an idle Y trunk, this rotation being directly controlled vcontrol of these olf normal springs tended te retard the movement of this shaft. ln my present invention l control these springs by means entirely independent of this switch shaft. i

These and other novel features and advantages of my invention will be more readily understood by reference to the'acconpanyino drawings, infwhich l have illustrated a switch embodying the features of my invention in connection with an automatic system lof the well-known Strowger type.

Figure l shows a complete connection between a calling substation A and a called substation A.

Fig. 2 is a detail view of a portion of the central oliice apparatus.

The system in connection with which l have chosen to illustrate my invention is of the local battery .type and of that kind in v which Hint selectors are employed indiT g magneti@ and a rotary magnet 17.

vidual switches for the telephone lines. 'In Fig. l'the connection is shown extending through the first selector E, which is individual to the calling substation A, and through a connector switch F to the called substation A. rl"he selector E is the indi. vidual selector' of the called substation A. At B there is shown a battery having one terminal grounded at Gr for the purpose of supplying current for operating the central oliice apparatus.

p The -substations shown yherein .comprise the usual receiver 2, transmitter 3, induction coil/l, switch hook 5, ringer 6 and local battery 7. In addition to theusual telephone apparatus abovepointed out, the substation is also provided with an automatic calling device of any suitable character for producing the necessary kind of impulses for 0perating' the central ollice switches. This calling device, however, may be 0f any other suitable type. rlhe one shown herein coin-` prises essentially a pair of impulse springs 8 and 9 and a toothed impulse wheel 105 which latter is controlled through the medium of a dial (not shown) in such a man- K ner that upon its operation to call any digit the impulse spring S is forced into contact with the ground post ll a number of times, corresponding `to the digit called, after which the impulse spring 9 is forced intoV contact with said post once. Such a calling device is in general well known in the art and is fully described in United States Letters Patent to E. l). Fales, No. 866,639, issued September 24, 1907, and it is not thought necessary to give a detailed description of the same herein.

The selector E is of the general type of selector switches disclosed in United States Letters Patent No. 815,321, issued March 18, 1906, to Keith, Erickson and Erickson, with the usual sideswitch omitted and the cir-` cuits modified, as will be described hereinafter. This selector includes' a bank of contacts arranged in rows or levels and adapted to be engaged by `a set of wipers 13, il and 15 carried upon la vertically and rotatably movable shaft (not shown) the movement of which is controlled by a so-called vertical The operations of the switch are controlled hv the calling subscriber through the medium of the usual vertical and rotary `line'relays 18 and 19, The magnet 20 is the usual vrelease magnet for restoring the switch to normal-position after it haspbeen operated. The wipers 13V and 14.- are connected with the line conductors through normally closed contacts of a switching relay 21. This relay direction.

I have provided novel and improved means for operating the said contacts 2%? and 24h, which means is clearly shownin Fig.` 2. Heretofore, such o normal springs v have been controlled by a cam on the switch 25y shaft which, as long as the switch shaft was in its normal rotary position, engaged a bushing on one of the springs so as to maintain the contact in its normal position. When the switch shaft was rotated this cani passed out of engagement with the bushing and allowedl the contact to assume its operated position. This manner of controlling the rotary off normal Contact is objectionablevin that the engagement of the cani with the bushingon the spring interferes with the free motion of the switch shaft in a vertical direction.v As shown in Fig. 2,' these rotary 'off normal springs are controlled by the armature 'of the rotary magnet instead of by the switch shaft. Fig. :2 is a more or lessl diagrammatic view of a section of the switch shown in 'said'PatentNo 815,321, referred l to above, said section being taken on a horizontal` plane Just above the rotary magnet.

In this figure, 17'represents the rotary magnet, its armature and 76 the usual'switch shaft. 77 is the usual double dog for maintaining the switch shaft in an operated condition. The double dog 77 is pivoted at the point 78. Secured to the back of the switch frame there is a pair of contact springs 24 and 24h and an additional flexible spring member 79, which, at itsriorward free end, is bent over in front of the rotary'armature 75. In the bent-over portion of the spring '79, there is an opening which is adapted to be engaged by a short pin in the front ofthe rotary armature. The rear end ot the .double dog 77 Yis alsoextended back far enough so/that when` said dog is withdrawn fromr theV shaft it will forceV the spring 7 9 inward tothe position shown in Fig.

Upon lthe lii'st vertical operation of the `switch the vdouble dog drops into the teeth ofV the shaft in the usual manner, and the released and moves outward under its own tension to force the spring 21th into Contact with the spring 2l, When the double dog is withdrawn from the switch shatt upon the release of the connection, its rear portion forces the spring 79 back into its normal position, whereupon the pin 8O again engages the opening in the end of the spring 79 so as to lock it in this position until the rotary magnet is again energized.

The connector F is of the general type of connector switches disclosed in United States Lett rs Patent to Keith, Erickson and Erickson, No. 815,176, issued March 13, 1906. Like the selector, the connector is provided with a set of wipers 24, and 26 which are carried upon a vertically and rotatably movable shaft, the movement ol which shaft is controlled b v the usual vertical and rotary magnets 27 and QS. The usual side switch comprising the wipers 29, 30, 31 and 32 is controlled by the private magnet in the usual and well-known. manner. 3l is the release magnet. The operation oilE the vswitch is controlled through the medium of the usual vertical and rotary line relays and 3G. 37 is the ringer relay the t'unctioii of which is to'control the application of ringing current to the called line 'for signaling the called subscriber. it L a ringing current generator is shown andy ai M there is represented a busy signaling machine for supplying the usual busy signaling current to notify the calling subscriber when the called line is in use.

The selector E and the substation A are the same the selector E and the substation A, respectively.

. rifhe construction and operation oi my improved selector switch will be more readily understood by the following description of the operation of the system described. In order to call. the substation A the subscriber at the substation A. first removes his receiver from the switch hook, then operates his calling dial in accordance with the respective digits or" the number of the called substation, which in this case will be assumed to be 220. Upon the initial movenient oi the subscribers dial for thel iii-sV digit Q, the substation ground G is connected with the ground post 11 by the closure of the Contact 36. .is the dial returns to itsv normal position, the Contact between the springs S and 1l is closed twice, whereby two impulses ot current are transmitted over thel circuit extending from the substation -ground G through the contact B6, springs 11 and 8, line 37, selector line relay 18 and springs 38 to the battery lead Ll0,

and thence through the battery B to ground Gr. Each time the relay 18 is energized in response to these impulses, an impulse is and 15 to the battery lead 10. rlfhe vertical magnet 16 operates in response to these impulses to raise the switchshaft twoI steps to carry the wipers 13,14: and 15 to a position opposite the second row. or level of the bank contacts. The closure of, the contact 23 upon ,the first verticall movement of the switch shailft connects the battery lead 40 with the release `magnet 20, while at the Sametime the closure of the contact 22 connects the rotary line relay 19 to batteryin dependent ot the contact between the springs 15 andati. After the two impulses are `transmit/ted `,over the vertical line by the substation impulse spring 8, the rotary impulse spring 9 is forced into contact with the ground post 11, whereby a single iinpulse is transmitted over the rotary line L17 through the rotary line relay 19, springs i8 andspringstt and 45 in n'iultiplewith the contact 22 tothe ba'tterylead L10. The relay 19, upon energizing, closes a circuit Vextending from ground G2, through the springs 19 and 50, rotary magnet 17 and the relay 21 in multiple, springs dei and to the battery lead 10. The rotary magnet, upon energizing, rotates the wipers one step onto the terminal of the first trunk line in the second level, to which level the wipers were raised.

'by the operations ot the vertical magnet hereinabove described. The relay 21 is energized in multiple with the rotary linagnet and by opening the contacts 51 and 52 disconnects the line wipers 13 and 1-1 from the line while they are being rotated. 1t this first trunk line, upon the terminal oi which the wipers have been rotated, is not already in use7 the relay 21 denergizes shortly after the in'ipulse is transmitted through the rotary magnet and completes the connection between the calling line and the trunk line. 1f, however, this iirst trunk line is already in use, the private wiper 15 iinds the Contact which it engagespi ovided with a. guarding ground potential. This guarding potential is supplied through some other occupying switch in a .manner whichV will be fully described hereinafter. Upon the engagement ot the wiper 15 with the Grounded contact et a busv line and while the relay 21 is energized, a circuit is closed from said grounded Contact through the wiper 15springs 53 and 541e, rotary line relay 19, springs e8 and contact 22 to the battery lead 40. `The rotary line relay 19 thereupon immediately energizes and aga-in closes the circuit ot the rotary magnet 17 and the `:relay 21.* AThe rotaryrmagnet 17, upon energizingrotates ythe wipers a second step land breaks the circuit of the relayV 19 at the springs 4:8. The relay 19 thereupon de'e'nergizes, breaking the circuit of the magnet 17, whichin turn denergizes and again closes the circuit of the relay 19. 1t will. thus be `seen that as long as the wiper 15 continues to engage grounded contacts, the circuit ot' the rotary magnet 17 will be periodically interrupted to rotate the wipers 13, 1d andvl step by step over the contacts ot thebusytrunks. The relay 21, which is energized in multiple with the rotary niagnet` 17, being slow acting does not denergize between the impulses, and therefore remains in its operated position continuously while the wipers are being rotated and thus keeps the line conductors 37 and j17 disconnected from the wipers while they are passingover the contacts ot the busy trunks. When i the.` wiper l5 passesv on the` last grounded contact, the energizing circuit for 24J), and through said springs 55 and 53 and the private` wiper 15 to the selector private bank contacts ot' the seized trunk. Ar guarding potential is extended to the connector private bank contacts of the calling line immediately upon the first rotary step ot the selector, said potential extending trom ground Gf* through the coitacts 24e and 24" .and over the conductor 57 to said contact.

Upon the denergization oit the relay 21 att-er the last rotary step ot the selector, a circuit is closed through the battery cut-oiti` relay 58, which circuit extends from ground G4 through the springs 2i and 2li", relay 5S and springs 3S to the battery lead L10. The relay 58, upon energizing, disconnects the battery troni the vertical and rotary inagnets.

The apparatus is now in position to receive the impulses for the second digit oi.i the called number. These. impulses pas through the wipers and 14; of the selector E and thence to the connector it. These inn pulses operate this connector in the wellknown manner to step the saine up, first, to the second level and then around to the tenth Contact in this level, which contact belongs to the` desired called subscriber.V 1Jilhen this connection is completed, a guarding potential is `placed upon the connector private bank contact ot the called iine in the wellknown manner in order to` prevent a second connectionbeing made with this line. y

Inorder to signal the called subscriber the calling subscriber presses `the ringing button162, whereby the vertical line 37 is is temporarily open and the ringingA current generator L is connected with Lthe called line. Y, Y

y After the conversation is completed the central otiice apparatus is released by the hanging up of lthe receiver at the calling substation. This is accomplished in the following mai'iner:Y As the switch hook descends, the springs 64, and 66 areall pressed into contact simultaneously, whereby both sidesB'T and L7 of the calling line are groundedat the same time. The 'simultan'eous grounding of the conductors 37 and 47 eneigizes the line relays`v 18 and 19 and 35 andtirot both the selector E and the connector F. In the connector F the energizationoi the relay 36 closes the circuit of the private magnet 33 in the usual manner. The relay 85, upon energizing, at the same' time closes a circuit from ground G9 through the springs G7, 68, 69, and the springs 71 and the release magnet 34 to the battery lead 440. VThe magnet 3st, upon energizing immediately lrestores the mechanism of the connector switch to normal position. In the selector E the simultaneous energization of the relays 18 and 19 closes the circuit ot the release magnet 20,'this circuit extending Lbs from ground 'G2 through the springs 41, springs l2 and v79, magnet 2O and the contact 23 to the battery lead 40. The magnet 20, upon energizing, attracts its armature and holds it in readiness to release the switch upon its back stroke .when the switch hook descends far enough to break the circuit of the line relays 18 and 19 to allowV them to denergize to open the circuit of the release magnet. Y

It' will thus be seen that I have devised a very etlicient torni of side switchless selector and one in which the, positive operation thereof is secured. Y

lVhile I have `illustrated one particular embodimentof my invention, and have shown the same in connection with a particular automatic'system, it is, of course, understood that many changes will readily suggest themselves to those skilled the art and come within the broader scope of my invention. Likewise, my improved selector switch is not limited Vto use in connection Y nectingsaid telephonefwith the central-office, an automatic switch, trunks accessible to-saidl switch, said trunks divided into groups, said switch having means for electing a group of'tiunks by one motion and for thereafter finding a line in the group by a second motion, a first relay in one of said line conductors, a second relay in the other of said line conductors, said lirst relay :tor controlling said rst motion, a motor inagiiet for moving the switch to iind a line, said magnet vand said second relay controlling each others circuits.

2. In a telephone system, a plurality of trunk lines divided into groups, a selecting switch having one motion to select groups and another motion to select an idle line in the selected group, a line relay for controlling tlie lirst movement, a second line relay, an operating magnet controlled by said second line relay tor controlling the second motion ot said switch, a third relay connected in multiple with said operating magnet, and a circuit for said second line relay controlled by said third relay.

3. In a telephone system, a plurality ot trunks divided into groups, an automatic selecting switch having one motion to select groups and anotherniotion to select an idle trunk in the predetermined group, a relay for controlling said second motion, manual means for initially energizing said relay over the line circuit to cause said switch to be operated one step, and automatic means tor then energizing and denergizing said relay to operate said switch to select an idle trunk.

et. In a telephone system, a plurality of trunk lines divided into groups, a selecting rswitch haring one motion to select groups and another motion to select an idle trunk in the predetermined group, a line relay, an operating magnet controlled thereby, a second relay controlling an. energizing circuit ior said line relay, manual means for initially energizing said line relay to ope `ate said switch one step. and a circuit for said line relay controlled by said second relay for automatically energizing said line relay one or more times to operate said switch to select an idle trunk.

5. In a telephone system, a plurality ot trunk lines divided into groups, a selecting switch having one motion to select groups and another motion to select an idle trunk in the predetermined group, a line relay, an operating magnet controlled thereby, a scc ond relay connected in multiple with said operating magnet and controlling an energizing circuit for said line relay, manual means for initially energizing said line relay to operate said switch one step, and a circuit tor said line relay controlled by said second relay for yautomatically energizing said line relay one or more times to operate said switch to select an idle trunk.

6. In a telephone system, a plurality of trunk lines divided into groups, a selecting switch having one motion to select groups and another motion'to automatically select an idle trunk in a group, a line relay indi* vidual to said switch, line wipers for said switch by which said switch connects with said trunks,tan operating magnet for controlling the second movement of said switch in response to the operation of said line relay, and arelay connected in multiple with said operating magnet for disconnecting said line wipers from said switch during said second movement.

7. 1n a telephone system, a plurality of trunk lines divided into groups, a selecting switch having one motion to select groups and another motion to automatically select an idle trunk in a group, a line relay individual to said switch, line wipers for said switch by which said switch connects with said trunks, an operating magnet for con- Y trolling the second movement of said switch in response to the operation of said line relay, and a slow acting relay connected in multiple with said operating magnet for disconnecting said line wipers from said switch duringfsaid second movement.

8.1n a telephone system, a plurality of trunk lines divided into groups, a selecting switch having one motion to select groups and another motion to automatically select an idle trunk in a group, a line relay, an operating magnet for'controlling said second movement controlled by said line relay, an energizing circuit for said line relay controlled by said operating magnet, a second relay connected in multiple with said operating magnet, and means controlled` by said second relay for controlling the circuit of said line relay.

9. ln a telephone system, a plurality of trunk lines divided into groups, a selecting switch having one motion to select groups and another vmotion to automatically select an idle trunk in a group, a line relay, an operating magnet for controlling said second movement controlled bv said line relay, an energizing circuit for said line relay con trolled by said operating magnet, a second relay connected in multiple with said operating magnet, means controlled by said second relay for controlling he circuit of said line relay, a pair of line wipers for said switch, and means controlled by `saidrsecond relay for disconnecting said line wipers from the switch during said second movement thereof.

10. In a telephone system, a selecting switch comprising a switch shaft, means for moving saidshaft firstY in one direction and ond motion, a pair of contacts normally` separated, and means controlled by said magnet for closing said contacts upon the initiation of the second motion of said shaft for controlling a guarding potential circuit associated with the switch.

l2. in a telephone system, a selecting switch comprising a switch shaft, means for moving said shaft in one direction and means, comprising a magnet, for then moving the shaft in another direction to find an idle trunk, a pair of contacts normally sepav rated, and means controlled by said magnet for closing said contacts upon the Y initiation of the second motion of said shaft by said magnet to control a guarding potential circuit associated with said switch.

13. In a telephone system, a selecting switch comprising a switch shaft, means for moving said shaftfirst in one direction and again in another direction to find an idletrunk, a pair of contacts normally separated,

means independentV of the switch shaft forl closing said contacts upon the initiation of the second motion of said shaft to control a guarding potential circuit associated with the switch, and means controlled by the release of said switch for again separating said contacts.

1st. ln a telephone system, a selecting switch comprising a switch shaft, means for moving said switch in one direction and means, comprising a magnet, for then moving the shaft in another direction to find an idle trunk, a pair of contacts normally separated, means controlled by said magnet for closing said contacts upon the initial rota-` tion of said shaft to control a guarding potential circuit associated with said switch,

and means controlled by the release of said switch for again separating said contacts. Signed by me at Dayton, Montgomery county, Ohio, this 6th day of June, 1912.

CHARLES w. stamina.

topics of 'this patent may be obtained for ve cents each, by addressing the Commissioner ct Patente, Washington, 

